The use of large winches mounted upon vehicles or relatively fixed, large winches driven by their own power source is well-known in the art. These known winches are necessary and useful items but there must of necessity be access by which the bulky equipment can reach the desired location or alternatively there must be a large enough demand for the winch to justify the building of a road or other access means whereby the winch may be transported to the location of intended use.
There has developed a need for a small portable winch which can be carried to inaccessible areas by hand and be attached on site to a portable power source. The demand for timber has increased to the point where it is being harvested from terrain previously ignored because of the expense and/or inconvenience. The suburbanite, the hunter and the gentleman farmer find need for a large pulling power and would like to have assistance in this operation without investing a great deal of capital. In addition, a need has been developed for a small portable winch with high capacity pulling power relative to its weight and size which may be used in conjunction with a mobile power source such as a chain saw engine.
Many people have a chain saw at their disposal. It is, of course, extremely desirable to be able to use the engine of the chain saw in conjunction with a portable winch without structural change to the saw itself. It is also desirable to be able to rapidly convert a chain saw to use the same engine with a portable winch. Rapid conversion without structural change in the chain saw allows use of the saw in both modes without severely hindering the use for which it was designed.
Small winches which are adapted to be powered by engines such as chain saw engines are known as shown by U.S. Pat. No. 2,869,822 issued Jan. 20, 1959, and U.S. Pat. No. 3,197,162 issued July 27, 1965. Although these patents teach driving a small winch by means of a chain saw or other portable power source, they do not disclose any means for level winding the cable on the drum. This is extremely critical during outfeed of the cable for smooth and uniform feed and is important in wrapping the maximum amount of cable about a drum. Level winding avoids serious damage or destruction of the cable which frequently occurs when randomly or loosely wound cable about a winch drum is subjected to severe tension loading.
It is an object of the present invention to provide a small winch adapted to be powered by a light weight prime mover wherein the winch includes, as an integral part thereof, means assuring that the cable will be wound upon the drum in a plurality of smooth layers.
It is another object of the present invention to provide an attachment to a small portable winch so that the winch, although secured to a dead man, may pivot about a vertical axis causing the cable to sequentially and smoothly wrap across the drum, first in one direction and then in the other.
Still another object of the invention is to provide a small portable winch which pivots about a vertical axis and which has a forwardly extending cable guide to restrict the relative angle of approach of the cable to the winch and provide means for causing the cable to smoothly move up to the next layer when reaching the end of the drum on any given particular layer, thus assuring a smooth and level wind.